Strapping machine



STRAPPING MACHINE 7 Sheets-Sheet l Filed Jan. 30, 1961 Jan. 2l, 1964 F..1. LINDHOLM STRAPPING MACHINE '7 Sheets-Sheet 2 .Im/@1 7 wlw/w,

Filed Jan. 30, 1961 Jan. 21, 1964 F. J. LINDHOLM STRAPPING MACHINE- '7Sheets-Sheet 3 Filed Jan. 50, 1961 I Inga/d0?? @ga/wmwm @mmm/awww 4.455.I

Jan. 21, 1964- F. J. LINDHOLM STRAPPING MACHINE '7 Sheets-Sheet 4 FiledJan. 30. 1961 'IMM E? '7 Sheets-Sheet 5 J luga: (if u@ ge/'MMM nafu/Jan. 2l, 1964 F. J. LINDHOLM STRAPPING MACHINE Filed Jan. 30. 1961 F. J.LINDHOLM STRAPPING MACHINE Jan. 21, 1964 7 Sheets-Sheet 6 Filed Jan. 30,1961 F. J. LINDHOLM STRAPPING MACHINE Jan. 21, 1964 '7 Sheets-Sheet '7Filed Jan. 30, 1961 Y lllllllllllllllllllllllllllllll Il.

United States Patent Office ll? Patented dan. 2l, i964 Filed `lan. 30,i961, Ser, No. $5,913 14 Claims. (Cl. Mill-4) This invention relates tostrapping apparatus, and is particularly concerned with apparatuscapable of strapping an article as it is being moved along alongitudinal path of travel by a conveyor, without stopping or slowingthe conveyor or the article carried thereby.

While embodiments of this invention have general utility and may be usedin many environments, there is described herein an illustrativeembodiment effective to perform a strapping operation for simultaneouslystrapping two oppositely disposed portions of a coil of material beingmoved by a conveyor.

In this embodiment of the invention, the strapping apparatus comprises apair of strapping machines 'that are interconnected electrically andmechanically to enable them to be normally operated simultaneously onopposite sides of a coil of material that is moved longitudinallythrough a strapping zone. rlhe apparatus is normally automatic, but italso includes hand operated controls for operating different parts ofthe apparatus separately if so desired or in the event of anymalfunction and to facilitate servicing.

The coils of material to be strapped are carried individually on hookssuspended from an overhead conveyor chain that is continuously driven inany suitable manner. A photo-electric system, generally referred to asan electric eye is disposed to observe the coils as they enter thestrapping zone. lf any hook passes through the strapping Zone without acoil mounted on it, the light beam of the system is not interrupted, andthe strapping apparatus is not operated.

A coil mounted on one of the hooks activates the strapping apparatus byinterrupting the light beam to the photo-electric cell as the coilenters the strapping zone. The strapping apparatus is so timed that itstarts the strapping operation as a coil of material breai s the lightbeam upon entrance of the coil into the strapping Zone, and completesthe strapping operation and returns the mechanism to its starting orrest position before the next hook enters the strapping zone in thenormal operation of the conveyor and strapping apparatus.

Each strapping machine is mounted on a movable carriage, and thecarriages are interconnected mechanically by a common shaft coupled tothe drive shaft of each cai riage to synchronize the longitudinalmovement of both carriage The strapping machines face each other, andeach is mounted on a cross slide that moves it inwardly toward the coilthat is carried through the strapping zone between the two machines bythe longitudinally moving conveyor. The machines strap an arcuateportion of the ring formed by the coil at each of two diametricallyopposite positions and apply a metal seal to the strap as the coilpasses through the strapping Zone.

When a coil breaks the light beam at the entrance to the strapping zone,a drive arm swings downwardly from each of the carriages into thelongitudinal path of travel of the coil. Each drive arm has apositioning block secured thereto and projecting from the drive armtoward the entrance end of the strapping Zone. lf a coil mounted on oneof the conveyor hooks hangs so that one edge of the coil strikes apositioning block before the other does, the forward edge of the coilengaging one positioning block is held stationary against itspositioning block, and the conveyor hook continues to move the otheredge of the coil until both edges of the coil are in Contact with thepositioning blocks.

Each positioning block has a switch mounted thereon. The switches are inseries so that both switches must be closed before the circuit isenergized. When both switches are closed the head of each strappingmachine moves inwardly, and other switches mounted on the strappingmachine heads engage opposite edges of the coil and are closed thereby.The switch on each head swings a pair of chute arms inwardly to closethe arms inside the coil. Each chute has a switch that is actuated byclosing the chute, to start the strap feeding mechanism. The switches onthe chutes are in series with the switches on the strapping machinehead, so that the chutes must be closed before the strap can be fed.Each chute is provided with a gate that isl closed to confine the strapthat is fed into the chute by each strapping machine. The chute islarger in circumference than the circumference of the circular portionof the coil, and therefore the strap forms a loose loop around saidcircular portion of the coil.

The carriages on which the strapping machines are mounted are each heldagainst longitudinal movement by an air cylinder. When the conveyor hookstrikes a switch on either drive arm the air cylinders are vented, andboth carriages are released for longitudinal movement. Both carriagesare moved longitudinally by the engagement of the conveyor hook with thedrive arms, and, therefore, must move at the same speed as the hook. Thestrapping operation is continued as the hook moves the carriages towardthe discharge end of the strapping zone. The electrical circuits are sointerconnected that when the strap encircles a portion of the coil thestrap feeding mechanism is stopped, the gates are opened, and the strapis pulled tight around the circular portion of the coil to tension it.The chutes are opened after the gates are opened to re-set them for thenext coi1 to enter the strapping zone. When the strap has beentensioned, a metal seal is applied to seal two overlapping portions ofthe strap and the strap is cut off.

When the strap is cut olf the strapped coil is free to move out of thestrapping zone. The cylinders for driving the carriages bach to theirstarting position are provided with air cushions to decelerate them asthey approach the end of their movement to prevent an abrupt stop at theend of the longitudinal movement of the carriages.

An illustrative embodiment of the invention and a structure by means ofwhich the above noted and other advantages of the invention are attainedis described in detail inthe foliowin specification, taken inconjunction with the accompanying drawings, in which:

FIG. l is a fragmentary front elevational view of a strapping apparatusembodying the invention;

FIG. 2 is an end elevation, taken from the right hand side of FlG. l,with parts broken away to clarify the illustration;

FlG. 3 is an enlarged top plan View of the apparatus shown in FlG. l,with the vertical portion of the con,- veyor hook shown in section;

FlG. 4 is a cross sectional view, the line 4,-4 of FlG. 3;

FlG. 5 is a view, partly in elevation and partly in section showing onechute and its related structure;

FlG. 6 is a cross sectional view, taken along the line 6-6 of FlG. 5;

FlG. 7 is a cross sectional View, taken along the line 7-7 of FlG. 5;

FIG. 8 is a cross sectional View, taken along the line Sw?. of FlG. 5;

FIG. 9 is a cross sectional View, taken along the line 9--9 of FlG. 5;

FIG. lO is a cross sectional view, taken along the line lli-lll of FlG.3;

taken generally along FIG. 1l is a pneumatic circuit diagram of the rearstrapping apparatus remote from the operator; and

FIG. 12 is a view, similar to FIG. 1l, for the front strapping apparatusin front of which the operator normally stands.

The illustrative embodiment shown in the drawings comprises twostrapping machines 11, 12 mounted on longitudinally movable carriages13, 14. The strapping machines are essentially similar to the machineshown in the Crosby et al. Patent No. 2,915,003. It should beunderstood, however, that the present invention is not limited to usewith any specific strapping machine, and that any suitable strappingmachine may be used. It should also be appreciated that embodiments ofthe present invention may use a single strapping machine when it is notdesired to apply a pair of straps simultaneously to an object. Eachstrapping machine has a head that contains mechanism for performing thevarious strapping operations, and a chute for guiding the strap aroundthe article to be strapped. The strapping head is the same as thatdescribed in the above mentioned patent and, therefore, is not describedin detail herein.

The carriages 13, 14 are mounted in spaced relationship on oppositesides of a conveyor adapted to move a series of hooks 15 along apredetermined path of travel extending longitudinally in one directionthrough a strapping Zone between the carriages 13, 14. The conveyormoves the hooks back to their initial position along a path of travelremote from said strapping machines. Each hook comprises a verticalsection 16 that is secured to an overhead chain (not shown), and ahorizontal section 17 adapted to carry a coil 18 of material to bestrapped. The material of the coils may be bars, rods or strips of metalor any other material that can be iandled in coil form.

The carriages 13, 14 are duplicates, and therefore only one of them willbe described in detail, it being understood that the description appliesto both carriages. The structure of the carriage is shown best in FIG.4. The carriage is supported on a bed 19 having a pair of side walls 20,21 and corner posts 22. Leveling screws 23 are provided for each post toinsure accurate leveling of the bed. A shaft 24 is journalled inbearings 25 mounted in each side wall. Suitable couplings 26 at one endof cach shaft 24 connect each of the shafts 24 to an intermediate shaft27 axially aligned with the shafts 24. The coupled connection betweenthe shafts synchronizes the rotational `tovemcnt of both shafts and thelongitudinal movement of both carriages, as hereinafter described.

The bed 19 has two intermediate coplanar horizontal plates 28, 29extending inwardly from side walls 20, 21, respectively. The inner edgesof the plates 28, 29 are spaced from each other to provide a space for aplate 30 for supporting an air cylinder 110 (FIG. 1) from which a pistonrod 31 projects. After completion of each strapping operation the pistonrod moves carriage 13 back to its initial position in a mannerhereinafter described. A plurality of transversely disposed angle irons32 support longitudinally extending plates 33 that support the inneredges of plates 28, 29. Ears 34 projecting laterally from opposite edgesof support plate 30 are secured to the inner edge portions of plates 28,29 by bolts 35.

The carriage 13 is provided with a ilat bed plate 36 movablelongitudinally on the bed 19. The bed plate has a flange 37 dependingfrom each longitudinal edge, and the flanges are provided with apertures38 in each of which a tubular sleeve 39 is rigidly secured. A bearing 40has a shaft 41 extending through the sleeve 39 and secured thereto by anut 42. The bearings are rotatably mounted in longitudinally extendingrecesses 43 in the side walls 20, 21. The bearings provide a rollingsupport for the carriage as it is moved longitudinally relative to thebed 19.

A longitudinally extending bar 44 secured to plate 29 by bolts 45 servesas a xed guide for the longitudinal movement of the carriage. A plate 46depending from the bed plate 36 has a horizontal flange 47 extendingtherefrom to support a pair of laterally spaced vertically disposedbearing shafts 48 secured thereto by a nut 49. A roller 59 is rotatablymounted on the lower end portion of each bearing shaft 48. The rollers50 engage opposite edges of guide bar 44 to provide rolling contacttherewith as the carriage is moved longitudinally in either direction.Each roller is spaced from the underside of ilange 47 by a sleeve 51.The frictional Contact between the rollers 50 and the guide bar 44 isnot suillcient to interfere with the longitudinal movement of thccarriage.

A carriage link 52 having its upper end secured to plate 46 by bolts 53has an aperture through which the outer end of piston rod 31 extends. Anut 54 secures the piston rod to the carriage link. 'The lower end ofthe carriage link is secured to an endless chain 55 that extends arounda sprocket 56 mounted on shaft 24 and another sprocket 57 (FIG. 1)spaced longitudinally therefrom. The sprocket 57 is mounted on an idlershaft 558 journalled in bearings (not shown) in walls 20 and 21.

When the carriage is moved longitudinally in either direction thecarriage link moves the chain 55 to rotate the shaft 24. Theintermediate shaft 27 and couplings 26 rotate the other shaft 24 tosynchronize the longitudinal movement of the carriages 13, 14. Thecarriage is moved in the same direction as the movement of the coilthrough the strapping zone by the conveyor hook 15 in a mannerhereinafter described. The carriage 13 moves the piston rod 31 outwardlyas it is moved by the hook 15. The carriage is moved back to its initialposition by the piston rod 31 after the hook has moved out of thestrapping zone. The end of the return movement of the piston rod isdeceleratcd by a valve 118 that is operatively connected thereto in anysuitable manner. The valve 118 is enclosed in a housing 579 having anarm 60 projecting therefrom and terminating in a clevis 61. A lug 62rigidly secured to the lower edge portion of the flange 37 by a bolt 63,depends into the clevis and is secured thereto.

The strapping machine is mounted on the bed 19 in a manner to permittransverse movement of the strapping mechanism relative to the bed. Thehead of thc strapping machine is secured to a cross slide 64 mounted onball bearings 65, one of which is shown in FIG. 10. The ball bearingsare housed in races 66 supported by plates 67 projecting upwardly fromthe bed. A piston rod projecting from a cylinder 111 moves the crossslide transversely of the bed.

A cover plate 68, supported in a suitable manner, extends over the bed19 and moves longitudinally with respect to the bed plate 36. The outerend of the cover plate 63 is supported on an extension plate 69 (FIG. l)by rollers 70. The rollers 70 are each rotatably mounted in a bracket 71secured to the underside of the cover plate.

Each carriage is provided with a drive arm 72 (FIG. 2) having a basesection 73 and an upper section 74 pivotally mounted on the outer end ofthe base section, as indicated at 75. The pivotal connection 75 alsosecures a bell crank 76 to the drive arm. The lower end of the basesection 73 is secured to the carriage adjacent the side that is remotefrom the entrance of the strapping zone and also remote from theconveyor. The base section is angular and its upper end extends towardthe conveyor. A cylinder 112 mounted on the base section 73 has a pistonrod '/'7 connected to one end of the bell crank. Another cylinder 78mounted on the base section has a spring biased rod 79 connected to theopposite end of the bell crank.

When the apparatus is in its rest position the spring biased rod 79holds the upper section of the drive arm upwardly out of the path oftravel of the coils 18. The cylinder 112 is operated by an electric eyesystem, hercinafter described, to lower thc upper arm section into theattese? path of travel of the coils when the conveyor moves a coil intothe strapping Zone. The upper end of the drive arm is engaged by theconveyor hook to move the carriage longitudinally a limited distance.When the carriage has reached the end of its normal movement a limitswitch energizes an electrical circuit that is effective to exhaust thecylinder lil The spring biased rod 79 then moves the upper section ofthe drive arm upwardly out of the way of the coil which is carried pastthe drive arm to a discharge station.

A switch ltlSl is associated with the upper section of each drive arm.The switch may be mounted directly on the drive arm, but it is preferredto mount it on a positioning block Si) secured to the drive arm. Thepositioning block projects from the drive arm toward the entrance of thestrapping zone so that the switch mounted thereon will be engaged by thecoil before the coil engages the drive arm. The positioning block isslidable transversely of the drive arm, as indicated at Sti', FIG. 3.The positioning block slides the coil rearwardly on the conveyor hookuntil the conveyor hook i engages the drive arm. The engagement of theswitch ltlS with the coil initiates the strapping cycle, as hereinafterdescribed. Mounting the switch llilSl on the positioning block in spacedrelationship to the drive arm allows more time for the strappingoperation. l

A lswitch i251 is mounted on the outer end or the upper section of thedrive arm in position to be engaged by the hook of the conveyor. Whenthe conveyor hook engages switch i231 and closes it the rst result isthat an air cylinder il@ is vented. The cylinder il@ normally holds diecarriage i3 against longitudinal movement. The hook of the conveyorexerts pressure against the drive arm 72 to move the carriagelongitudinally until the strapping operation is completed.

The chute assembly 82 shown in FlG. 5 has a pair of coacting chute arms@3, fili each of which is rigidly secured to a sleeve 35 that ispivotally mounted on a vertical post Se, 87. The posts 83, 39 of asecond chute assembly Eil are closely spaced, as shown in FIG. 3. rl`hisdifference in the post spacing is necessary because one strappingmachine is reversed, and it is desirable to have both chute assembliesaligned with the coil so that they can encircle diametrically oppositeportions of the coil simultaneously. The structure of chute assembly 9@will not be described specifically, since the structural characteristicsof both chute assemblies are essentially the same.

The lower end of each vertical post is lixed in a base support @l by aset screw 92., as shown in FlG. 1G. The base support 9i is mounted onthe cross slide 64 and moves with the head of the strapping machine. Thebase support has an upstanding wall 93 to which a support bracnet 94 anda horizontally disposed channel 9S are secured. The upper end of thepost is supported in vertical position by the support bracket 9d. Thesleeve S5 ts over the post but is cut away, as indicated at 6, to permitthe support bracket 94 to engage the peripheral surface of the post. Thesleeve 35 may be made in two sections rigidly secured together by anysuitable bridge member. The sleeve d5 has bearings 97, 93 adjacent itsupper and lower ends. A pinion gear 99 projects laterally from thevertical sleeve 8S. The pinion gear is preferably integral with thesleeve, but may be a separate member rigidly secured thereto. A coverplate lull fits around the exposed portion of the pinion gear as aprotective cover.

A rack 301 is slidably mounted in the channel 95 and meshes with thepinion gear 9. A cylinder 113 has a piston rod 362. Rack Sill is movedback and forth in the channel $5. The cylinder 113 is operated by anelectrical circuit that includes the switches ltlSl, MS2. Limit switchesSlA, SSlA mounted adjacent opposite ends of channel 95 are actuated byone end of rack 301 and by a collar or clamp 393 mounted on the oppositeend of the rack, as the raclr is reciprocated in the channel 95. Thereciprocation of the rack 301 oscillates the chute assembly by rotationof the pinion gear 99 in opposite directions.

As shown in FIG. 5, the sleeves S5 are positioned at opposite sides ofthe strapping machine head. Chute arms 83, Sd;- have straight sections394, 3%, respectively, extending from each sleeve along diverging lines.The outer end of section Stil-l terminates in a curved section 3%, andthe outer end of section 395 terminates in a curved section 367. A web3% (Pi. l0) extending between each sleeve $5 and the adjacent curvedsection 3th?, Sii? provides a rigid reinforcement that helps to supportthe chute assembly. The curved sections of the chute arms cooperate toencircle a circular portion of a coil l in engagement with the switchesltlSll, 1082 on positioning blocks A strap gate Sil@ having an invertedLshaped cross section is mounted on a ilat block Titti comprising twojuxtaposed sections Sil., 312 secured to the cross slide ed. A limitfinger 313 is secured to the end of the cross slide to overhang one edgeof strap gate 369. The vertical flange of strap gate Citi@ is spacedfrom the edge of section Sil to provide a narrow gap 314 through whichthe strap is threaded. A strap gate Sie adjacent the other side of thestrapping machine has a gap 31.6 through which the free end of the strapis threaded as it is pulled from a supply source. A Contact block 317depends from section in position to be engaged by the strap being fedthrough the chute. When the contact block is engaged by the free end ofthe strap being fed through the chute it triggers a time relay which,after a predetermined time delay, reverses the current to stop a strapfeeding motor. Stopping the motor stops the strap feeding movement.

The strap gate Sti@ is held against the upper surface of block Si@ by acam 13 pivotally mounted in a carn guide .319 by means of a pin 32d. Thecam guide is rigidly secured to the upper surface of the section 394 ofchute arm 53 in any suitable manner. The cam is urged into position inwhich the strap gate is held down against the upper surface of blockEdil by a spring 321. The spring 321 is seated in a recess 322 insection 3M and is secured to a guide pin 323 that is positioned in anaperture 3124i in the cam.

After the strap feeding movement is stopped it is necessary to open thestrap gate to allow the strap to be tensioned around the portion of thecoil which it encircles. An air cylinder 1li@ is mounted below anaperture 325 in the chute arm 83 and actuates a plunger 326 to move thegate upwardly to allow the tensioning mechanism of the strapping machineto pull the strap out of the chtite. When the gate is opened and thestrap is pulled out of the chute, the pressure against plunger 326 isreleased, and the gate is pulled down by a spring 327 that is assistedby gravity.

The spring 327 is mounted on a bushing 328 and extends upwardly into acounterbored recess 329 in block Sill. A rod .i3-il having one endsecured in the bushing 32S extends through the recess 329 and isthreaded into an aperture in the strap gate, as indicated at 33t, FG. 7.The spring encircles the rod 336i andrat its upper end bears against awasher 332.

A clear understanding of the sequence of operations of the strappingmechanism may behad by reference to the schematic,electricpneumatic-mechanical illustrations shown in FiGS. ll and 12,inclusive. rl`hese iigures clearly show and fully disclose all of thepneumatic and electric wiring connections and the interrelationstherebetween. Moreover, the elements of the electrical system arenumeralled and lettered to indicate the correspondence thereof with eachother. For example, the relays and the contacts thereof, respectively,have corresponding numerals and letters to identify the same. rl`hefollowing discussion describes the operating relation of the electric,pneumatic and mechanical arrangements and functions with reference tothe fully disclosed systems shown in the drawings which form a part ofthis specication.

The master control panel for the simultaneous operation of bothstrapping machines is located on the front of strapping machine 11 whereit is easily accessible to the operator.

For automatic operation of the mechanism, a selector switch is turned toautomatic position to energize the automatic circuits and to lock outthe hand controlled circuits. It will be assumed that the strappingmechanism is in its starting position in the following description ofthe operation.

A coil 18 mounted on a conveyor hoolt is moved into the strapping zoneby the conveyor. The coil breaks a light beam between a light and aphoto-electric cell receiver to energize the solenoids D1, D2. Thesolenoids D1, D?. operate valves for the cylinders 112, 212 and therebycause the drive arms 72 to lower into the path of longitudinal travel ofthe coil. Switches 1281, 1282 are in series with the electric eye systemand must be closed or the drive arms cannot move downwardly. Thedownward movement of the drive arms opens switches 581, 582.

A positioning block 80 is secured to each drive arm and is spaced fromthe drive arm toward the entrance of the strapping zone, so that as thecoil is moved along with the hook of the conveyor longitudinally ofthemachine, it will engage the positioning blocks S before the hook engagesthe drive arms 72. Switches 1081, 1G82 are mounted on the positioningblocks and are closed by contact with the coil 18 being moved by theconveyor hook. The switches 1081, 1082 are in series, so nothing canhappen until both switches are closed.

If one edge of the coil 13 engages one of the positioning blocks, saidone edge will be held stationary in contact with said bloclt as themovement of the conveyor hook moves the other edge of the coil intoengagement with the other positioning block so that the coil is properlypositioned for the strapping operation. When the coil engages bothpositioning blocks it closes both switches 1081, 1082 and energizes thesolenoids B1, B2, C1, C2. The solenoids C1, C2 operate the cylinders111, 211 to move the heads of the strapping machines inwardly intoengagement with the edge portions of the coil. The engagement of thestrapping machine heads with edge portions of the coil closes switches381, 382. The solenoids B1, B2 operate the cylinders 113, 114, 213 toclose the chutes 82, 90. As the chutes are closed they open switches781, 781A, 782 and close switches 881, 381A, 882 to start the strapfeeding operation. The switches 881, 881A are in series with switches381 and 1081, and the switch 882 is in series with the switches 382 and1082. Therefore, the chutes must be closed, and the head must be inengagement with the coil, before the strap feeding movement can start.The switches 1081, 1082 could be located on the drive arms, but it ispreferred to mount them on the positioning blocks to start the strappingcycle sooner.

As the coil moves toward the drive arms, the strap is fed through theeye of the coil. A contact block 317 mounted on the chute is engaged bythe strap being fed into the chute. The contact block triggers a timerelay which, after a time delay, reverses the current to plug the motorsto a stop, thereby stopping the strap feeding movement and de-energizingthe solenoids El, E2. The deenergization of the solenoids E1, E2operates the cylinders 120, 220 to open the gates 315 and permittensioning of the strap. When the gates are opened they close switches981, 982 to de-energize the solenoids B1, B2 and operate the cylinders113, 114, 213. The cylinders 113, 114, 213 open the chutes 82, 90 andstart the tensioning cycle.

As the conveyor continues to move the coil longitudinally through thestrapping zone, the hook is moved into engagement with switches 1281,1282 that are mounted on the drive arms 72. The hook closes the switches1281, 1282 to de-energize the solenoids A1, A21 to vent the cylinders110, 210 so that the carriages 12, 13 can be moved along with theconveyor. The carriages are moved by the engagement of the hook with thedrive arms, and therefore must move at the same speed as the conveyor.

When the sealing operation is completed and the strap is cut, theswitches 181, 182 are opened to fle-energize the solenoids C1, C2, D1,D2. The dc-energization of solcnoids C1, C2` operates cylinders 111, 211to withdraw the strapping machines from the sides of the coil 18. Thede-energization of solenoids D1, D2 causes exhausting of the cylinders112, 212 to permit spring biased rods 79 to raise the drive arms 72clear of the conveyor hook. Movement of the heads of strapping machines11, 12 away from the sides of the coil closes switches 481, 482. Upwardmovement of the drive arms closes switches 581, 582, opens switches 281,2812, 1281, 1282, and encrgizes solenoids A1, A2 to operate cylinders110, 210 through thc valves 168, 208 to drive the carriages back totheir starting positions.

As the carriages are driven back to their starting positions thecylinders 110, 210 are exhausted through valves 105, 167, 236, 267. Cams250, 251 mounted on the carriages close valves 118, 218 that are alignedwith valves 1F36, 2&6 to close them to restrict the exhaust iiow, andthereby form an air cushion to decelerate the pistons in cylinders 110,219 as they approach the end of their movement as the carriages returnto their starting position.

Normally the mechanism is operated automatically as a continuous processwith a new cycle started every time a coil carried by a hooi: of theconveyor breaks thc beam to the electric eye. However, if any part ofthe mechanism malfunctions, the cause of the malfunction misst becorrected before normal operation can be resumed. lt is not practical toservice parts of the mechanism while the automatic control is energized,and therefore hand operated control means has been provided for serviceand test purposes. The procedures for correcting the operation of themechanism depends upon the nature of the malfunction.

lf the limit switches 381, 382 are not actuated by contact with thecoil, or it the switches 881, 881A, 882 are not actuated because thechutes are unable to close, after a timed interval the chutes open, thedrive arms raise, the strapping machines retract, and the carriagesreturn to rest position. The coil that is not properly strapped isremoved, and the loose coil signal is reset by pressing a signal resetbutton. The machine will strap the following coils.

If either strapping machine fails to function properly, the loose coilsignal is actuated, but the other strapping machine will finish itsstrapping operation. The chutes open, the drive arms raise, thestrapping machines retract, and the carriages return to their startingposition. The loose coil signal cannot be reset until the malfunction iscorrected and the start button is pressed to re-energize the machine.The machine will not strap the following coils until it is cleared andre-energized.

If the carriages are carried to within three inches of the end oftravel, the limit switches 681, 682 are actuated to stop the conveyorand de-energize the control circuits. The chutes open, the drive armsraise, and the strapping machines retract. The malfunction must becleared and the carriages moved off the limit switches before thecircuit can be re-energized by pressing the start button.

In order to service the machine it is necessary to change from theautomatic control to hand control. This is done by turning a selectorfrom automatic position to hand position. This energizes the handoperation circuits and locks out the automatic circuits. The loose coilsignal is activated and cannot be reset until the selector is turnedback to automatic position. The conveyor stops when the automaticselector is turned to hand operation, but may be started again byturning the conveyor stop selector to ov-aride position. A pilot lamp onthe panel board lights when the automatic selector is turned to handoperation, and remains lighted until the automatic selector is turnedback to automatic position. A plurality of manually operated switchesactuate each mechanism separately to facilitate locating and correctingany malfunction.

Although a preferred embodiment `of the invention is described inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, rather than restrictive, as many detailsmay be modied or changed without departing from the spirit or scope ofthe invention. Accordingly, it is not intended to restrict the inventionto the exact construction described.

l claim:

l. In combination for cooperative operation with a con veyor having amovable member adapted to carry an article to be strapped, a carriagemovable along a line parallel to said conveyor, a strapping machinemounted on said carriage, said carriage being disposed in the path ofand engageable by an article carried by said movable member to move saidcarriage and said strapping machine in the same direction as saidarticle, means to limit the movement of said carriage in the directionof movement of said article, means for actuating said strapping machineto strap an article carried -by said movable member before said carriagereaches the limit of its movement in said direction, means to disengagesaid strapping machine from said article after the strapping operationis completed, and means to move said carriage back to its initialposition.

2. ln combination for cooperative operation with a conveyor memberadapted to move an article along a lixed path of travel, a strappingmachine movably mounted adjacent the path of travel of said article, apair of chute arms mounted on said strapping machine, means including amember engageable by said conveyor to move said strapping machine alimited distance in the same direction and at the same rate of speed assaid article, means to actuate said chute arms to encircle said articleand guide a strap around said article, said strapping machine beingadapted to feed a strap through said chute yarms and to apply it to saidarticle as said article and said strapping machine are being moved, saidstrapping machine being operated within predetermined travel limits tocomplete the strapping operation before it reaches the limit of itsmovement in said one direction.

3. ln combination for cooperative operation with a conveyor memberadapted to move a coil of material in one direction, a pair of strappingmachines positioned on opposite sides of the path of travel or" saidcoil, means to move both of said strapping machines a limited distancein the same direction and at the same rate of speed as said coil, meansto operate said strapping machines simultaneously to apply straps todifferent portions of said coil as said coil and said strapping machinesare being moved in the same direction, and means to insure completion ofthe strapping operation before said strapping machines reach the limitof their movement in the direction of the movement of said coil.

4. in combination for cooperative operation with a movableconveyormember adapted to move an 'article along a fixed path of travel,means including a drive arm for movably mounting a strapping machineadjacent said path of travel, means to move said drive arm into saidpath of travel as said conveyor member moves an article into proximityto said strapping machine, said drive arm moving said strapping machinein the direction of movement of said conveyor, and means to actuate saidstrapping machine to apply a strap to an article being moved along saidpath of travel by said conveyor member, said last mentioned meansincluding a switch mounted on said drive arm, said switch being adaptedto be closed by engagement with said article being moved by saidconveyor member.

5. In combination for cooperative operation with a movable conveyormember adapted to move an article along a xed path of travel, meansincluding a drive arm for movably mounting a strapping machine adjacentsaid path of travel, means to move said drive arm into said path oftravel as said conveyor member moves an article into proximity to saidstrapping machine, said drive arm moving said strapping machine parallelto said article, and means to actuate said strapping machine to apply astrap to an article being moved along said path of travel by saidconveyor member, said last mentioned means including a switch mounted onsaid drive arm, said switch being adapted to be closed by engagementwith said article being moved by said conveyor member before saidconveyor member moves into engagement with said drive arm.

6. In combination for cooperative operation with a conveyor memberadapted to move a coil of material in one direction, a pair of strappingmachines positioned on opposite sides of the path of travel of saidcoil, a pair of chute arms mounted on each of said strapping machines,means in engagement with said conveyor for supporting and moving both ofsaid strapping machines a limited distance in the same direction and atthe same rate of speed as the speed of said coil, and means to actuatesaid chute arms simultaneously to close each pair of them around adifferent portion or said coil, said strapping machines including meansfor 'feeding straps through said pairs of chute arms as said coil andsaid strapping machines are being moved in the same direction, and meansfor operating said strapping machines within predetermined limits tocomplete the strapping operation before they reach the limit of theirmovement in the direction of movement of said coil.

7. ln combination, two longitudinally movable carriages mounted inspaced relationship, a strapping machine mounted on each of saidcarriages, a conveyor member adapted to move a coil of materiallongitudinally lbetween said strapping machines, and means for actuatingeach ot' said strapping machines when a coil is moved between saidstrapping machines, said means including switches connected in series tobe engaged by said coil to actuate both strapping machines substantiallysimultaneously.

8. ln combination, means mounting two strapping Inachines in spacedrelationship including a drive arm disposed adjacent each of saidstrapping machines, a conveyor adapted to move a coil of materiallongitudinally between said strapping machines into engagement with saiddrive arms, and a positioning block projecting from each of said drivearms, said positioning blocks being adapted to hold one edge portion ofa coil against longitudinal movement as said conveyor moves the oppositeedge portion of said coil longitudinally, to center said coil relativeto said strapping machines.

9. ln combination for cooperative operation with a conveyor memberadapted to move an article along a lined path of travel, means includinga drive arm for movably supporting a strapping machine adjacent saidpath of travel, said strapping machine having a pair of chute armsadapted to guide a strap around an article when the chute arms are inthe closed position, a switch adapted to actuate movement of said chutearms to close them, said switch being positioned in said path of travelwhereby it is engaged by said article and moved into closed positionthereby, said conveyor member being engageable with said drive arm aftersaid chute arms have been closed to move said strapping machine alongwith said article.

l0. ln combination for cooperative operation with a conveyor memberadapted to move an article along a xed path of travel, means including adrive arm for movably supporting a strapping machine adjacent said pathof travel, said strapping machine having a pair of chute arms adapted toguide strap around an article when in closed position, a switch adaptedto actuate movement of said chute arms to close them, said switch beingpositioned in said path of travel whereby it is engaged by said articleand moved into closed position thereby, said conveyor member beingengageable with said drive arm after said chute arms have been closed tomove said strapping machine along with said article, and means foroperating said strapping machine to apply a strap to said article assaid article and said strapping machine are being moved by said conveyormember.

l1. In combination, two carriages mounted in spaced relationship, astrapping machine mounted on each of said carriages, a conveyor memberadapted to move a coil of material longitudinally between said strappingmachines, a drive arm connected to each of said carriages, an electriceye system adapted to cast a beam of light across the path of travel ofa coil carried yby said conveyor member, an electrical circuit energizedby interruption of said beam of light to move said drive arms into thepath of travel of said coil, and means including a switch to actuatesaid strapping machines, each of said switches being adapted to beclosed by engagement with an edge portion of a coil being moved betweensaid strapping machines.

12. In combination, two longitudinally movable carriages mounted inspaced relationship, a strapping machine mounted on each of saidcarriages, a conveyor member adapted to move a coil of materiallongitudinally between said strapping machines, a drive arm connected toeach of said carriages, an electric eye system comprising means to casta beam of light across the path of travel of a coil carried by saidconveyor member and an electric eye responsive to said beam of light togenerate signals upon decrease of luminosity upon interruption of saidbeam of light, an electrical circuit activated by said signals to causemovement of said drive arms into the path of travel of said coil, meansfor actuating said strapping machines, said means including a first anda second switch mounted on each of said drive arms, each of said firstswitches being adapted to be closed by engagement with an edge portionof a coil being moved between said strapping machines, means for holdingsaid carriages against longitudinal movement, said second switches beingengageable by said conveyor member when said drive arms are in the pathof travel of said coil to release said holding means, said conveyormember being adapted to move said carriages in the same direction assaid coil upon release of said holding means.

13. In combination, two carriages mounted in spaced relationship, astrapping machine mounted on each of said carriages, a conveyor memberadapted to move a coil of material longitudinally between said strappingmachines, a drive arm connected to each of said carriages, said conveyormember being engageable with said drive arms to move said carriageslongitudinally, a fluid pressure operated cylinder for holding each ofsaid carriages against longitudinal movement, a switch mounted on eachof said drive arms, said switches being engageable by said conveyormember to actuate said cylinder to release said carriages for limitedlongitudinal movement by said conveyor member, and means for actuatingsaid cylinders after said limited longitudinal movement to move saidcarriages back to their initial position.

14. In combination for cooperative operation with a conveyor having amovable member adapted to carry an article to be strapped, a carriagemovable along a line parallel to said conveyor, a strapping machinemounted on said carriage, said movable member being engagcable with saidcarriage to move said carriage and said strapping machine in onedirection along a line parallel to said conveyor, means to limit thenormal movement of said carriage in said one direction, means foractuating said strapping machine, said strapping machine being timed tostrap an article carried by said movable conveyor member before saidcarriage reaches the limit of its normal movement parallel to saidconveyor in said one direction, and a switch in an area beyond thenormal limit of movement of said carriage and in the path thereof, saidswitch being operable upon engagement by said carriage to stop saidconveyor and to de-encrgize the strapping machine.

References Cited in the le of this patent UNITED STATES PATENTS1,261,589 Mogan et al Apr. 2, 1918 2,901,966 Becher Sept. 1, 19592,905,078 Laine Sept. 22, 1959 2,915,003 Crosby et al Dec. 1, 19592,930,313 Bocher Mar. 29, 1960 FOREIGN PATENTS 744,176 Great BritainFeb. 1, 1956 OTHER REFERENCES German printed application 1,087,514, Aug.18, 1960.

1. IN COMBINATION FOR COOPERATIVE OPERATION WITH A CONVEYOR HAVING AMOVABLE MEMBER ADAPTED TO CARRY AN ARTICLE TO BE STRAPPED, A CARRIAGEMOVABLE ALONG A LINE PARALLEL TO SAID CONVEYOR, A STRAPPING MACHINEMOUNTED ON SAID CARRIAGE, SAID CARRIAGE BEING DISPOSED IN THE PATH OFAND ENGAGEABLE BY AN ARTICLE CARRIED BY SAID MOVABLE MEMBER TO MOVE SAIDCARRIAGE AND SAID STRAPPING MACHINE IN THE SAME DIRECTION AS SAIDARTICLE, MEANS TO LIMIT THE MOVEMENT OF SAID CARRIAGE IN THE DIRECTIONOF MOVEMENT OF SAID ARTICLE, MEANS FOR ACTUATING SAID STRAPPING MACHINETO STRAP AN ARTICLE CARRIED BY SAID MOVABLE MEMBER BEFORE SAID CARRIAGEREACHES THE LIMIT OF ITS MOVEMENT IN SAID DIRECTION, MEANS TO DISENGAGESAID STRAPPING MACHINE FROM SAID ARTICLE AFTER THE STRAPPING OPERATIONIS COMPLETED, AND MEANS TO MOVE SAID CARRIAGE BACK TO ITS INITIALPOSITION.